The Mind: Somewhere between Unknown Forces and Biology
The principal disagreement between Darwin and the positions of Wallace concern the mind. Wallace was attracted not only by mesmerism and phrenology but by the spiritualism that was developing in the United States.48 He talks about ghosts, telepathy, and the communication between the dead and the living. He is not speaking of belief, but from a conviction based on numerous experiences that he evaluated critically. He identifies two levels of the mind:49
1. A level of the mind that is intimately linked to the shape of the body and to behavior as described by German neurologist Franz Josef Gall. This level corresponds to the instinctive and emotional innate behaviors and to some know-how, like the use of tools. This type of behavior is subject to the rules of the theory of evolution.
2. Other mental forces are not directly linked to the shape of the body. These are potential resources that will not develop outside of particular social contexts, like the spiritual resources activated by religious instruction. To the extent that evolution only selects activated behaviors, it is therefore not possible to explain the potential resources of the human mind with a biological theory.
For Wallace, evolution advances in small increments. The changes in mental capacity between humans and monkeys are so important that they cannot be explained by the small steps of biological evolution.50 Some mental capacities are more developed in one culture than in another. These are referred to as potential capacities. An individual born in the wild can go to London and become a pianist who plays classical music.51 If such a person had stayed in the wild, this potential capacity would have never expressed itself. Therefore, it cannot have been selected by biological processes. It is probably because of this argument that scientists eliminated Wallace from the current references related to the theory of evolution. On that point (mind and evolution), Lamarck remains the reference.